Abstract
Nano α-Al2O3 powders were prepared by thermal decomposition of ammonium aluminium carbonate hydroxide (AACH). The effects of α-Al2O3 crystal seeds, reactant concentration, content of active agent (PEG), annealing temperature and ZnF2 addition on the preparation of nano α-Al2O3 powder were studied. The results showed that nano α-Al2O3 powder with apparent crystallite size ∼40 nm could be prepared, and the complete transformation temperature of α-Al2O3 could be reduced from 1250 to 1050°C as α-Al2O3 seeds and ZnF2 were added. The prepared nano α-Al2O3 powders were characterised by X-ray diffraction (XRD), differential thermal analysis and thermogravimetric (TG-DTA) and scanning electron microscopy (SEM). A back propagation (BP) artificial neural network (ANN) has been used to establish models between the relative content of the nano α-Al2O3 powders and the preparation parameters. The results of checking experiments were in accordance with the calculated values.